Effects of Boron on the Emergence and Allocation of Metabolic Compounds in Two Herbaceous Cotton Cultivars

High boron (B) concentrations in the soil can cause toxic effects to plants, so herbaceous cotton (<i>Gossypium hirsutum</i> latifolium Hucth) is a crop sensitive to such stress. Thus, this study aimed to evaluate the emergence, partitioning, and allocation of metabolic compounds of two herbaceous cotton cultivars subjected to B treatments. The experiment was carried out in a greenhouse, under a completely randomized design in a 2 × 4 factorial scheme, using two cultivars and four concentrations of B in the form of boric acid: 0.5 (control), 30, 60, and 120 mg dm^-3 B. The increase in the concentration of B in the soil generated a significant toxic effect on the growth and biomass of the cotton plant. Cultivar 1-TMG 50 WS3 obtained greater emergence and shoot growth, while cultivar 2-FM 911 GLTP invested in roots; however, in both cultivars, B remained accumulated in the shoot. There was an increase in amino acids in the roots and a decrease in proteins and phenolic compounds in leaves and cotyledons. It was concluded that the seedlings presented satisfactory emergence up to 60 mg dm^-3 B, and that among the cultivars there are distinct responses to B application.